Shoptask 1720 XMTC parts

Afternoon, I have a 1993 vintage Shoptask 1720 XMTC and am looking for an upgrade or plans for a lead screw reverse upgrade for this machine.

I've contacted Shopmaster and been told that its no longer available.

Can anyone point me to an option for parts or plans for the modification for the reversing lead screw mechanism?

Thanks!

Rich